1. Field of the Invention
The present invention relates to a socket connector for electrically connecting an integrated circuit to a printed circuit board, especially for connecting a land grid array socket connector to a printed circuit board.
2. Description of the Prior Art
Modern computer systems increase in performance and complexity at a very rapid pace, driven by intense competition and market demands. In order to meet ever-increasing performance requirements, the area and volumetric interconnect densities of electronic board assemblies must increase accordingly. In combination with other competitive forces, this demand has driven the need for improved high-density socket technologies in computer applications, and the connector industry has responded with a variety of new alternatives to meet these needs. One of the most attractive of the new connector types is the land grid array (LGA) socket connector, which permits direct electrical connection between an LGA integrated circuit and a printed circuit board. LGA socket connectors are an evolving technology in which an interconnection between mating surfaces of an IC or other area array device and a printed circuit board is provided through a conductive terminal received in the socket connector. Connection is achieved by mechanically compressing the IC onto the socket connector.
FIGS. 4–5 disclose a conventional socket connector 90 for electrically connecting an integrated circuit (IC) package 91 to a printed circuit board (PCB) 92. The conventional socket connector 90 comprises a plurality of contact terminals 93 received in an insulative housing 94, a stiffening body 95 surrounding the housing 94, a load plate 96 pivotably assembled with one end of the stiffening body 95 and a load lever 97 pivotably attached to the other end of the stiffening body 95. The housing 94 defines a recessed area 940 for receiving the IC package 91 therein and the recessed area 940 has a bottom wall 941. The housing 94 defines a multiplicity of arrayed passageways 942 through the bottom wall 941. Each passageway 942 forms an upper receiving channel 943 and a lower interfering channel 944. The interfering channel 944 is narrower than the receiving channel 943 and a step 946 is accordingly formed therebetween. Each terminal 93 includes a fastening portion 930 defining a pair of shoulders 931 at a top portion thereof. The fastening portion 930 further defines a plurality of protrusions 932 for interfering with the interfering channel 944. When the terminal 93 is installed into the housing 94, the shoulders 931 are secured in the receiving channel 943 and abut against the step 946, and the fastening portion 930 is interferentially received in the interfering channel 944. Each terminal 93 further includes a solder portion 933 extending from and substantially perpendicular to the fastening portion 930. A solder ball 934 is attached to the solder portion 933 for mechanically connecting the connector 90 on the PCB 92 by surface mounting technology (SMT).
However, when the connector 90 is shaken by an improper exterior force, the housing moves upwardly relative to the PCB 92, and the step 946 acts on the shoulders 931 directly. As the terminal 93 is soldered on the PCB 92, the force acted on the shoulders 931 by the step 946 will break the connection between the solder ball 934 and the PCB 92, and the connection between the solder ball 934 and the solder portion 933. As a result, the conventional socket connector cannot provide reliable connection between the IC package 91 and the PCB 92.
Hence, a new socket connector which overcomes the above-described disadvantages is desired.